An electron beam irradiation apparatus is designed to increase the etching resistance of a mask by irradiating the mask with an electron beam in a semiconductor device manufacturing process, for example.
There is a demand for a high-performance electron beam irradiation apparatus.
According to one embodiment, provided is a method of adjusting an electron-beam irradiated area in an electron beam irradiation apparatus that deflects an electron beam with a deflector to irradiate an object with the electron beam, the method comprising: emitting an electron beam while changing an irradiation position on an adjustment plate by controlling the deflector in accordance with an electron beam irradiation recipe, the adjustment plate detecting a current corresponding to the emitted electron beam; acquiring a current value detected from the adjustment plate; forming image data corresponding to the acquired current value; determining whether the electron-beam irradiated area is appropriate based on the formed image data; and updating the electron beam irradiation recipe when the electron-beam irradiated area is determined not to be appropriate.
According to another embodiment, provided is an electron-beam irradiated area adjustment system that adjusts an electron-beam irradiated area in an electron beam irradiation apparatus that deflects an electron beam with a deflector to irradiate an object with the electron beam, the electron-beam irradiated area adjustment system comprising: an adjustment plate that detects a current corresponding to an emitted electron beam; an ammeter that acquires a current value detected from the adjustment plate; an image forming module that forms image data corresponding to the acquired current value; a determiner that determines whether the electron-beam irradiated area is appropriate based on the formed image data; and a recipe updater that updates the electron beam irradiation recipe for controlling the deflector when the electron-beam irradiated area is determined not to be appropriate.
According to another embodiment, provided is an electron-beam irradiated region correction method implemented in an electron beam irradiation apparatus that is designed to irradiate a rectangular region as a target with an electron beam by applying a voltage V1(t) to a first electrode to perform scanning in a first direction with an electron beam from an electron beam generator, and applying a voltage V2(t) to a second electrode to perform scanning in a second direction with the electron beam, the voltage V1(t) varying with time t, the voltage V2(t) varying with time t, the second direction being perpendicular to the first direction, the electron-beam irradiated region correction method comprising correcting an electron-beam irradiated region to have a rectangular shape by applying a voltage V1(t)+kV2(t) (k being a constant) to the first electrode and applying the voltage V2(t) to the second electrode, when the electron-beam irradiated region is not a rectangular region but a parallelogram region distorted in the first direction.
According to another embodiment, provided is an electron beam irradiation apparatus that is designed to irradiate a rectangular region as a target with an electron beam by applying a voltage V1(t) to a first electrode to perform scanning in a first direction with an electron beam from an electron beam generator, and applying a voltage V2(t) to a second electrode to perform scanning in a second direction with the electron beam, the voltage V1(t) varying with time t, the voltage V2(t) varying with time t, the second direction being perpendicular to the first direction, the electron beam irradiation apparatus comprising an electron beam control device that applies a voltage V1(t)+kV2(t) (k being a constant) to the first electrode and applies the voltage V2(t) to the second electrode, when an electron-beam irradiated region is not a rectangular region but a parallelogram region distorted in the first direction, whereby the electron beam control device corrects the electron-beam irradiated region to have a rectangular shape.
According to another embodiment, provided is an electron beam irradiation apparatus comprising: an electron beam generator that generates an electron beam; a first electrode that deflects the electron beam from the electron beam generator in a first direction; a second electrode that deflects the electron beam from the electron beam generator in a second direction perpendicular to the first direction; and an electron beam control device that controls voltages to be applied to the first electrode and the second electrode, wherein the electron beam irradiation apparatus is designed to irradiate a rectangular region as a target with an electron beam by applying a voltage V1(t) to the first electrode to perform scanning in the first direction with the electron beam from the electron beam generator, and applying a voltage V2(t) to the second electrode to perform scanning in the second direction with the electron beam, the voltage V1(t) varying with time t, the voltage V2(t) varying with time t, and, when an electron-beam irradiated region is not a rectangular region but a parallelogram region distorted in the first direction, the electron beam control device applies a voltage V1(t)+kV2(t) (k being a constant) to the first electrode and applies the voltage V2(t) to the second electrode, to correct the electron-beam irradiated region to have a rectangular shape.